/**
 * Licensed to Jasig under one or more contributor license
 * agreements. See the NOTICE file distributed with this work
 * for additional information regarding copyright ownership.
 * Jasig licenses this file to you under the Apache License,
 * Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a
 * copy of the License at:
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.jasig.portal.portlets.search;

import java.io.Serializable;
import java.util.Comparator;

import org.jasig.services.persondir.IPersonAttributes;

/**
 * DisplayNameComparator allows the sorting of people by display name.
 * 
 * @author Jen Bourey, jbourey@unicon.net
 * @version $Revision$
 */
public class DisplayNameComparator implements Comparator<IPersonAttributes>, Serializable {
    private static final long serialVersionUID = 1L;

    @Override
    public int compare(IPersonAttributes o1, IPersonAttributes o2) {
        Object name1 = o1.getAttributeValue("displayName");
        Object name2 = o2.getAttributeValue("displayName");
        if (name1 == null && name2 == null) {
            return 0;
        } else if (name1 == null) {
            return -1;
        } else if (name2 == null) {
            return 1;
        } else {
            return name1.toString().compareTo(name2.toString());
        }
    }

}
